Automated fiber placement machines are widely used to manufacture parts, components and structures from composite material. The materials used in automated fiber placement are typically composed of longitudinal fibers and resin consolidated into tapes, or thin strips, commonly known as “tows.” Individual tapes or tows are manipulated by the fiber placement machine to form a band of material that is deposited onto a tool. Parts are built up layer-by-layer, with tapes or tows of composite material, with the angle at which each layer “ply” is laid onto the tool being precisely determined by the fiber placement machine.
Automated fiber placement enables the construction of complex composite structures having steered or curvilinear fiber paths. This method of producing composite structures is more cost effective than manual methods. It provides an improved structural efficiency due to its ability to orient the fibers along local internal loads paths, which potentially results in lighter structures and lower costs than in structures made by other production methods.
The individual tows of material are typically wound onto spools, stored in an environmentally-controlled structure known as a creel. A single creel may commonly include, for example, provisions for storage and simultaneous outfeed from 32 spools. During the fiber placement process, particularly on large parts, the tows stored on one or more of the spools may be completely used up, prior to completion of the part.
It is desirable, therefore, to provide a method and/or apparatus for replenishing the exhausted spool as quickly and efficiently as possible, so as to minimize interruption of the fiber placement process. In this regard, it would be highly desirable to provide a method and/or apparatus for replacing an entire creel, so that the fiber placement process may continue from a fresh creel, while the creel having one or more exhausted spools can be replenished off-line.